Fertilisers and phosphates—identify the wrong statement: Choose the option that is factually incorrect under standard industrial practice and agronomy for India.

Introduction / Context:
This item tests practical knowledge that bridges chemistry and field agronomy. Some statements describe core process thermochemistry, while others concern fertiliser application suitability in Indian conditions. You must select the incorrect statement among generally accepted facts.

Given Data / Assumptions:

• Industrial urea is produced via ammonium carbamate; the carbamate-to-urea step is endothermic.
• Wet-process phosphoric acid coproduces gypsum.
• Single superphosphate (SSP) results from reacting rock phosphate with dilute sulphuric acid.
• Indian agriculture spans hot, humid regions with significant volatilisation risks.

Concept / Approach:
Direct soil injection of anhydrous (liquid) ammonia is common in temperate countries with suitable equipment and soils. In tropical climates like much of India, high temperatures, smallholder field practices, and limited injection equipment make direct NH3 use impractical and prone to large volatilisation and safety issues. Hence the statement endorsing it as “suitable” is wrong. The other statements align with standard chemistry and process practice.

Step-by-Step Solution:

Verification / Alternative check:
Process texts show energy input for the carbamate dehydration section; fertiliser manuals describe SSP production via H2SO4 and widespread Indian use of urea/complex fertilisers rather than anhydrous NH3 injection.

Why Other Options Are Wrong (i.e., not the wrong statement):

• (a) True thermochemistry.
• (c) True wet-process by-product.
• (d) True for SSP manufacture.
• (e) True: AN neutralisation is exothermic.

Common Pitfalls:
Assuming practices from temperate mechanised agriculture transfer directly to tropical smallholder systems; overlooking safety and equipment constraints.

Final Answer:
Direct field application of liquid ammonia is suitable for a tropical country like India